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When to Plant Watercress in Hampshire County, MA

Hampshire County, Massachusetts Zone 6a May

Hampshire County, Massachusetts gardeners: here's your May plan

Your garden in Hampshire County, Massachusetts is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 30
Avg. first frost October 17
Soil temp (4") 56°F
Watering Moderate
Pest pressure Low
Daylight 14.4 hrs
Looking ahead to June
  • Starting indoors: watercress
  • First harvests: watercress

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Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.

Hampshire County, Massachusetts is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 17, giving you a growing season of approximately 170 days.

At an elevation of 518 feet, Hampshire County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Watercress during the growing season.

Hampshire County, MA (Zone 6a) Moderate season
170 days
Last Spring Frost April 30
170 growing days
First Fall Frost October 17

Hampshire County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (91 days to spare)
Start indoors: Mar 21 Transplant: Apr 25 🍅 Harvest: Jun 6 – Jul 11
Recommended (50%) ✓ Fits season (93 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 11 – Jul 16
Safe Start (90%) ✓ Fits season (90 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jun 28 – Aug 2

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Hampshire County

How your county's soil matches Watercress's growing requirements.

Soil pH

Your soil pH (5.2–6.2) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Hampshire County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Watercress.

How to Plant Watercress

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Watercress

5
successive plantings in your 170-day season

Sow every 4.6 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 827 gal / 100 sq ft

Monthly Watering Guide for Watercress

Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watercress Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 6.5" 3" 3.5" 🚿 Regular watering
May 6.5" 3" 3.5" 🚿 Regular watering
Jun 6.5" 3.9" 2.6" 💧 Light watering
Jul 6.5" 4.2" 2.3" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 2.8" 3.7" 🚿 Regular watering
Oct 6.5" 3.2" 3.3" 🚿 Regular watering
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hampshire County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Watercress Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Watercress needs ~725 GDD — county provides 2,465 GDD Excellent fit

Watercress Planting Timeline — Hampshire County, MA

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest June 11 Jun 11 – Jul 16
Fall Sowing August 8 Aug 8 – Aug 22

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

170 days in Hampshire County

Growing Tips for Watercress in Hampshire County

Direct sow Watercress outdoors after April 30 in Hampshire County when soil has warmed and frost danger has passed.

Your generous 170.0-day season in Hampshire County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.

Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watercress in Hampshire County, MA?

Hampshire County is in Zone 6a with an average last frost of April 30. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hampshire County, MA?

Hampshire County, Massachusetts is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 17.

🌱

Your Hampshire County Garden Planner — Free

A 24-page printable planner built for Hampshire County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hampshire County, MA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.